Weight operated switch



July 28, 1942.

L. P. LESSEM WEIGHT OPERATED SWITCH Filed July 3, 1941 INVENTOR.

flaw. BY 4:2

Patented July 28, 1942 UNITED STATES PATENT OFFICE 3 Claims.

This invention relates to weight operated switches, and relates more particularly to a novel circuit closing and opening device which is adapted to be used in association with a bed, the device having means for closing the circuit to light a lamp when a person leaves the bed, and to again open the circuit when the person returns to the bed.

One of the principal objects of the present invention is to provide a small compact circuitclosing unit, all mounted within an easily transportable housing, the device having means for attachment to the spring or mattress of the bed, and is so arranged that any appreciable downward movement of the mattress, as, for instance, that caused by a person lying on the bed, will open a circuit, and when the person leaves the bed the circuit will be instantly closed, thereby lighting a lamp, ringing a bell, or otherwise.

Another object of the present invention is the provision of a device of this character which will be particularly useful in hospitals to notify a nurse if and when a patient leaves the bed.

A further object of the present invention is to produce a weight-operated switch used in conjunction with a bed spring or mattress, wherein no adjustment of the elements is required for springs or mattresses of varying heights from the floor, it being only necessary to attach a cord leading from the device to a suitable portion of the spring or mattress, and then to move the housing to a proper position to enable the circuit to open and close when the person enters and leaves the bed, respectively.

Yet another object of the present invention is the provision of a novel alarm system including a circuit-closing device actuated by upward or downward movement of the mattress of a childs bed, whereby a nurse or other person in charge is instantly notified if the child should be surreptitiously removed from the bed.

A still further object of the invention is to provide a device of the character described which will aid in the cure of somnambulism in that the moment the sleepwalker leaves the bed a light may be lighted, or an alarm sounded, if such be necessary, to awaken the person, and repeated wakenings thus tend to condition the mind away from such practices.

Another object of the invention is the provision of an improved type of support for a mercurytype switch wherein the switch is caused to reverse its position, to open and close the circuit, by novel means remotely connected with the switch itself.

In the drawing:

Fig. 1 is a longitudinal vertical section taken through a preferred embodiment of the present invention.

Fig. 2 is a horizontal section taken on line 2-2 of Fig. 1.

Fig. 3 is a broken end elevation of the housing.

The preferred embodiment of the present invention includes a generally rectangular housing In, which may be made of metal, wood, or other material, the housing being provided with a door II on its upper surface, such door being hinged at l2 and being provided with a handle 13 to enable it to be opened. The door is further formed with an aperture I l through which a switch cord l5 passes, the cord having a suitable fastening element It at its upper end. At its lower end cord [5 is secured to a link 3 which is pivotally mounted at IE! on a vertical supporting element 20.

A removable base 22 is positioned on the lower wall 23 of the housing, and a second vertical supporting element 25 similar to element 2! is likewise mounted on base 22, vertical element 25 being slightly higher than element 28. An elongated arm 21 is pivotally mounted at 28 at the upper end of vertical support 25, the outer or free end of such arm being formed with an offset portion 30 lying at right angles to the arm, such portion engaging link l8 at a point substantially midway between the ends of such link.

A conventional mercury switch 32 is mounted on arm 2! in spaced relation thereto and substantially parallel therewith by means of a supporting element 33 which is secured to arm 21 by means of screws 3 A manually operated switch 36 having a pivoted lever 31 is mounted on upper wall 33 of the housing, and a conventional fuse receptacle 40 carrying a fuse H is mounted on lower wall 23 of such housing.

One end wall 42 of the housing is formed with an aperture 43 carrying a bushing 44 through which a cord 45 leading to the source of current passes, such cord having a male plug 46 at its outer or free end. The end wall is further provided with a female receptacle 48 which may receive a plug leading to the light or other element to be connected with the device.

In operation the'housing is placed under the bed, preferably near the center thereof, and hook element I6 is attached to the mattress (not shown). Adjustment of the device is made by merely moving the housing in one direction or the other to assure opening of the circuit when a person lies on the bed and closing of the circuit when the person arises from the bed. That is, the effective length of switch cord I5 is varied by movement of the housing when the hook element is secured to the mattress, so no special adjusting means is necessary.

Although only one embodiment of the invention is illustrated and. described herein, it is obvious that many changes and modifications may be made therein without departing from the spirit of the invention as defined by the appended claims. For instance, any circuit closing and opening device other than a mercury switch may be employed, although the mercury switch is preferred because of its positive operation and its relative safety. Also, if desired, lever l8 could be eliminated entirely and cord l5 attached directly to arm 21, or to the outer end of the mercury switch in the event that some means other than arm 21 is employed for reversing the position of the mercury switch.

What I claim is:

1. In a weight-operated switch adapted to be actuated by connection with a bed spring or the like to close a circuit when the bed is unoccupied and to open such circuit when the bed is occupied, the combination of a housing, a switch supporting arm pivotally mounted within the housing, a mercury switch carried thereby and being so disposed as to have its contact members elevated when the outer end of the arm is lowered, a pivotally mounted lever within the casing and arranged to elevate the outer end of the arm when the lever is manually raised, and means connecting the free end of the lever with the bed spring.

2. In a weight-operated switch adapted to be actuated by connection with a bed spring or the like to close a circuit when the bed is unoccupied and to open such circuit when the bed is occupied, the combination of a housing, a switch supporting arm pivotally mounted within the housing, a mercury switch carried thereby and being so disposed as to have its contact members elevated when the outer end of the arm is in a lowered position, a pivotally mounted lever within the casing, the outer end of the arm being supported by the lever, and means comprising a cord connecting the free end of the lever with the bed spring, whereby when the cord is raised upwardly, the lever will raise the arm and the switch carried thereby and thus close the circuit.

3. In a weight-operated switch adapted to be actuated by connection with a bed spring or the like to close a circuit when the bed is unoccupied and to open such circuit when the bed is occupied, the combination of a base member, a switch supporting arm pivotally mounted on the base member, a mercury switch carried by the arm and being so disposed as to have its contact members elevated when the outer end of the arm is lowered, a pivotally mounted lever within the casing, an extension portion of the outer end of the arm resting upon the lever substantially midway between the ends thereof and adapted to elevate the outer end of the arm when the lever is manually raised, and. means comprising a cord connecting the free end of the lever with the bed spring.

LEONARD P. LESSEM. 

